Search on Collapsible contents not working in angular

Question

I have implemented collapsible in my angular application. But those collapsible contents are coming from database service and I am setting those collapsible contents with the help of ngFor as-

 <input type="text" name="search" class="form-control" id="myInput" onkeyup="myFAQsSearchFun()" placeholder="Enter your query " >


 <div *ngFor="let item of faqs;let i = index;" id="div2">
     <button class="accordion" (click)="toggleAccordian($event, i)">
         <a style="text-decoration:none;" > {{item.question}}</a> 
     </button>

     <div class="panel"  hide="!item.isActive">
         <p><br> {{item.answer}} </p>
     </div>
     <br>
 </div>

Collapsible is working fine but the problem is that I want to search those contents based on what I type in search bar. For this I have implemented following code-

  function myFAQsSearchFun() {
                var input, filter, ul, li, a, i, txtValue;
                input = document.getElementById("myInput");
                filter = input.value.toUpperCase();
                ul = document.getElementById("div2");
                li = ul.getElementsByTagName("button");
                window.alert(li.length);
                for (i = 0; i < li.length; i++) {
                    a = li[i].getElementsByTagName("a")[0];
                    txtValue = a.textContent || a.innerText;
                    if (txtValue.toUpperCase().indexOf(filter) > -1) {
                        li[i].style.display = "";
                    } else {
                        li[i].style.display = "none";
                    }
                }
            }

Window.alert is giving output as "1". But ngFor loops for 3 times as I can see 3 collapsibles.

What I am doing wrong. Pls help.

Thanks in advance!

Answer 1

• Instead of using document.getElementById("myInput"), use Angular forms to get input.
• You will have the data that you have displayed in HTML available in controller, so instead of looping through DOM, you can just filter the Array in the controller itself.
• After filtering, just add a flag for each item in the FAQ to hide or show them.
• Add ngIF in the HTML based on the above flag.

HTML :

<input [(ngModel)]="model.search" >
<div *ngFor="let item of faqs;let i = index;" >
  <div *ngIf="!item.hidden">
     <button class="accordion" (click)="toggleAccordian($event, i)">
        <a style="text-decoration:none;" > {{item.question}}</a> 
     </button>

     <div class="panel"  hide="!item.isActive">
        <p><br> {{item.answer}} </p>
     </div>
     <br>
   </div>
 </div>

JS:

       model = {search: ''};
       faqs = [{question:'asf',answer:'asd'}, {question:'asf',answer:'asd'}]
       myFAQsSearchFun() {
            var input, filter, ul, li, a, i, txtValue;
            input = model.search;
            filter = input.toUpperCase();
            faqs.forEach((faq) => {
               if (faq.question.toUpperCase().indexOf(filter) > -1) {
                  faq.hidden = false;
               } else {
                  faq.hidden = true;
               }
            });
        }